June 26, 2021
Ireland, Northern Ireland

Bog standards

Invis Energy and An Bord Pleanála caused a bogslide in Donegal | By Anton McCabe | Village Magazine | 25 June, 2021 | villagemagazine.ie

Expert reports from objectors had warned of the strong possibility of a bogslide at Invis Energy’s wind farm at Meenbog, Co Donegal. Sure enough in November the millennia-old turf moved during construction work and has caused catastrophic damage to an SAC (Special Area of Conservation) and to an Area of Special Scientific Interest in Co Tyrone.

Objectors had warned as much, in reports submitted to An Bord Pleanála which had dealt with the application as a Strategic Infrastructure Development. It granted permission for 19 turbines on a 10 square kilometre site, including 22km of roads. Much of the site was blanket bog or upland bog, partly covered by mostly coniferous forestry.

During construction, it was planned to excavate and move a third of a million cubic metres of blanket peat, soil and rock and to fell 73.6 hectares (just under 182 acres) of forestry, planted on blanket bog. The trees had already weakened the bog. It was further proposed to dig three Borrow Pits. Rock needed for construction would be quarried from these. Then the excavated peat and soil would be deposited in them. This would be to a level of about a metre above the original ground level.

The Finn Valley Wind Action Group commissioned a report from Dr Pádraig Ó Catháin who pointed out that there were serious risks in building the windfarm in that location. “Borrow Pit 1 in particular, appears to be located in the vicinity of deep peat, was being built on blanket peat bog, and is an identified area in which construction should be avoided”, he wrote. “It is well known that commercial forestry degrades peat, reducing its strength and increasing the likelihood of a slope failure. This was identified as one of the key causes of the Derrybrien [Co Galway] bog slide”.

Ó Catháin’s conclusion reads, unfortunately, like a prediction: “As such AGEC [the environmental consultant] has failed to demonstrate that construction will not pose an unreasonable risk of soil failure and ensuing pollution to the surrounding area”.

Finn Valley Wind Action also commissioned another expert report from Professor Paul Johnson who laid out how the developer’s evaluation of drainage was inadequate. He, too, warned of a landslide. “Given the slope of the site and the density of infrastructure, the risk to surface water is high and suggests the overall unsuitability of this landscape for such a development”, he wrote in his report.

This report explained that development of the wind farm would cause not just increased volumes of run-off of water, but increased rates of run-off. “In such a high rainfall area and with this density of infrastructure, effective drainage will be difficult to achieve in a sustainable way,” Johnson wrote. Beneath the peat on the site there was an irregular rock surface. This led to pockets of liquid peat forming. He was critical of reports from the developer. “The evaluation of the hydrological and hydrogeological regime and the changes that would be expected from the development is inadequate for the risks involved”, he wrote.

Inspector Karla McBride, in her report to An Bord Pleanála, recommended granting permission. “I am satisfied that the results of the [Peat Stability Assessment Report – including the factor of safety analysis] are robust and that the proposed works would not give rise to peat instability or slippage…subject to the full implementation of the mitigation measures and any recommended conditions”.

She rejected the expert reports, writing: “I am satisfied that the proposed works would not have a significant adverse effect water quality [sic], sensitive aquatic species, the food supply for otters, or any designated ecological sites in the surrounding and wider area”.

A criminal investigation is underway North of the border. Posts on the Facebook page of the Derg Valley Community Angling Club reported significant numbers of dead fish in the Derg about 14 miles below Meenbog.

Donegal County Council has refused to comment publicly. However, it has issued enforcement proceedings under planning legislation, and at least twice under water pollution legislation. Residents in the area have confirmed most construction works on the site have now stopped.

They are, however, concerned that what appears to be a road has been built on site. Sinn Féin Councillor Gary Doherty wrote to Donegal County Council regarding this. In reply, the Council said “it may be a case that the ‘road’ you are referring to is an embankment that has been constructed to contain the area from where the original bog slide originated”.

Engineer Douglas Hill examined a picture of the works on behalf of Village. He said: “My assumptions include that a road is likely to be constructed on top of this embankment”.

A spokesman for company did not address the issue of the alleged road. He said: “In November a peat slippage occurred at the site. The area was quickly stabilised, with no risk to public health. We continue to work with the relevant authorities and are grateful to the local community for their continued support.”

Two years ago, Amazon committed to buying the wind farm’s output to power its data centres as a ‘green’ measure. It has not commented since the bogslide.